These 4 ounce hot cups are made with paper that is elemental chlorine-free (we have not yet found these cups in paper that is totally chlorine free), and they are coated on the inside with polylactic acid (PLA), which is made from agricultural crops such as corn and potatoes. They are fully biodegradable and compostable. There are no animal or petrochemical ingredients in the cups. For use with cold or hot (eg, boiling) liquids. Case of 1000. Eco Categories: Biodegradable, agriculturally based, less toxic, reuseable.